638308197 has 48 divisors (see below), whose sum is σ = 1025256960. Its totient is φ = 380851200.

The previous prime is 638308193. The next prime is 638308199. The reversal of 638308197 is 791803836.

It is a happy number.

638308197 is a `hidden beast` number, since 638 + 3 + 0 + 8 + 1 + 9 + 7 = 666.

It is not a de Polignac number, because 638308197 - 2² = 638308193 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638308193) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 278697 + ... + 280977.

It is an arithmetic number, because the mean of its divisors is an integer number (21359520).

Almost surely, 2^638308197 is an apocalyptic number.

It is an amenable number.

638308197 is a deficient number, since it is larger than the sum of its proper divisors (386948763).

638308197 is a wasteful number, since it uses less digits than its factorization.

638308197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2394 (or 2391 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 638308197 is about 25264.7619620688. The cubic root of 638308197 is about 861.0138561226.

It can be divided in two parts, 63830 and 8197, that added together give a palindrome (72027).

The spelling of 638308197 in words is "six hundred thirty-eight million, three hundred eight thousand, one hundred ninety-seven".